Open invitation to tender, deadline 14/04/2025, for studies relating to the civil engineering works required for the maintenance and refurbishment of the management and safety systems in the Onnens (600 m, 600 m), Concise (1340 m, 1365 m) and La Lance (420, 380 m) tunnels on the N05 between the Grandson and Vaumarcus junctions. The contract also includes studies and, depending on the results, the construction of 7 anti-recirculation walls - along the p.k.19,800-pk 31,000 section, for the adits of Sauges tunnel (1900 m, 1920 m), Chanelaz and Areuse cut&cover tunnels and for the west portal of the Gorgier tunnel (2754 m, 2754 m).
